Concrete stirring device



Feb. 21, 1933. c. E. MORROW CONCRETE STIRRING DEVICE 2Sheets-Sheet 1 Filed May 5, 1931 Feb. 21, 1933. c B MORROW CONCRETE surname DEVICE 2 Sheets-Sheet 2 Filed May 5. 1951 UyaeBMormw ii; $1 5M ,4 W

Patented Feb. 21, 1933 PATENT OFFICE:

CLYDE TB. MORROW, 0F SEATTLE, WASHINGTON CONCRETE STIRRING DEVICE Applicationfiled May 5, 1931. Serial No. 535,136.

My invention relates to hopper-body trucks, intended for the transportation of ready-mixed concrete from the mixing plant to a distant point of use.

It is recognized that there are certain limitations upon the use of ready-mixed concrete. Hopper trucks carrying the ready mixedconcrete can go only a given distance, that is to say, they can only allow the concrete to remain quiescent in the truck body for a given period of time, and thereafter it commences to set. -It must be discharged before that time is reached. When such trucks are impeded bytraiiic conditions, or perhaps become blocked by the raising of drawbridges, and the like, an emergency is created, and the load must be dumped to avoid it setting in the hopper truck. Furthermore, transportation of the ready-mixed concrete to any dis? tance will, to a certain degree, cause the aggregates to settle, and the mass loses its homogeneity.

On the otherhand,if the concrete within the truck body can be stirred up, not onlywill the settling of the aggregates be counteracted, but the concrete will not set. 'In consequence, it may be transported longer distances, if it is found necessary and economical to do so, and the load need never be dumped because of emergency conditions as indicated above. It has been found I also that its strength is little if any impaired by continued stirring over a reasonable period of time.

It is an object of my invention, then, to provide a means for incorporation in hopper truck bodies for maintaining a constant stir ring of the concrete within the body, to provide a construction whereby rocks largerthan the size usually employed, or any other fora. eign matter, if caught by the stirring device,

will not cause breakage thereof, to'providea device of this character which has the oints protected against the admission of concrete and sand, and to provide meanswherebythe entire bottom of a bullet-nosed hopper maybe kept clean, together withthe entirelength of the hopper. p v V 7 Other objects will be discovered upon study of the drawings, of this specification and of the claims. r

In the accompanying drawings I have shown my'invention in a form which is at present preferred by me, it being understood that various changes may be made in the details and in the driving means thereof, as will be evident to one skilled in the art to which this invention pertains.

Figure 1 is a side elevation of a hopper-bottom dump-body truck equipped with my invention. i, v

Figure 2 is a cross section thereof,

Figure 3 is a longitudinal axial section through the hopper body. I

Figure 4 is a detail elevation, parts being in section, and Figure 5 .is a cross section through the knuckle joint forming a part of my invention.

Figure 6 is a detail cross section through thegate hinge construction. I

The details of he truck, and to a large extent of the body, are immaterial. My inventhe hopper truck clean, and for stirring the concrete whenever necessary. As may be seen in Figure 1, the hopper-body 1 is pivotally tion is directed to the means for maintaining a mounted at 21 upon the chassis 2 of theautomobile, and the body 1 may be tilted to dump by a hoist means, not shown, which may take any suitableform, as is common in the art. When thus tilted, the gate 3, upon a pivot at 31, may be swung open upon release of a catch 30, the same being controlled by a handle 32 from the drivers seat 23 of the truck. Except for the particular type of hinge, these means are all common in the art. I prefer that the hopper body extend above the hinge 31, and have shown a plate 13 fixed in position above the gate.

As I have indicated, the hopper body. 1 may be of any suitable type, except that I prefer that it should be part-cylindrical, and my invention is particularly designed for employment with those hoppers which have a bullet nose, as indicated at 10. Thus, the body is semi-circular in cross section, as may be seen in Figure 2, with side walls 11 e2:- tending upwardly above the circular portion, and at the forward end the bullet nose 10 is part circular, both in cross section and in longitudinal section, as seen in Figure 3.

lVithin the hopper body 1, and preferably lying in the longitudinal axis thereof (or substantially so), is a shaft 4. This is suitably journaled in the plate 13 at the rear, as indicated at 40, and in the forward end of the bullet nose 10, as is indicated at 41. Upon this shaft, within the hopper body, are longitudinally spaced sets of spider arms 5. Preferably three of these arms a consti-- tute a set, and it is preferable that the sev eral sets be aligned longitudinally so that the corresponding aans of each set lie in the same radial plane. Ialso provide similar arms extending forwardly from about the center of curvature of the bullet nose'10, and extending at about a 45 angle to the shaft 1. If the hopper body is not provided with such a bullet nose, the arms 50 may, of course, be omitted.

These spider arms serve as indirect sup ports for flexible scrager members, represented by the chains 6 and 60. These chains are stretched longitudinally at the end of the spider arms and are joined thereto, or more properly speaking, they are joined to the outer ends of fingers 51, which are pivotally mounted at 52 upon the outer ends of the spider arms 5, forming a knucklejoint. The chains 6 and 60, then, are secured in eyes 53 at theouter ends of these fingers 51, and are drawn fairly tight, so that they will not, by the retardation of the concrete mass, be swung away from the bottom. As the spider arms 5 and their attached fingers rotate in the direction of the arrow A in Figure 4, the chains will be drawn over the curved surface of the hopper body, keeping the same bright and clean at all times, and serving also to stir up the concrete and to lift the heavy aggre gates which tend to settle so that they may be more evenly distributed throughout the mass.

It is obvious that the cha ns should er:- tend over substantially the entire length of the bottom of the hopper body, and the rear arm 5, may be seen in Figure 3, is bent somewhat so that its finger 51 may carry the end of the chain well into the corner just inside of the gate Similarly, the ordinary links of a chain, if extended from the forward arm 5 to the angular arm 50 and from the latter to the shaft 1, or thecollar 45 thereon, would extend across a chord if they were reasonably t ght, or if they were loose, the resistance of the concrete would cause them to be drawn upward away from the bottom. To prevent this, I have formed the chain of links which increase in size from each arm toward the opposite arm, so that the middle link of each section of this chain is the largest, and being large and being stretched fairly tight, the eXtra s ze of these central links will cause the chain to bear at all points along its length, compensating for the curve of the bullet nose.

The fingers 51, as has been indicated, are

pivotally mounted at 52 upon the ends of the spider arms 5, but since this knuckle joint is within the concrete while in operation, it is essential that it be protected against entrance of cement, sand and the like, and that it be made self-cleaning. Accordingly, I have provided an end-opening chamber 5% in the end of the arm 4., this being closed by the cover plate 55, between which cover plate and the opposite side of the chamber 5% the pivot pin 52 is journaled. The finger 51 is formed with aprons 56 at each side of its inner ends, which aprons retain the finger within the chamber 54: and bear against the walls thereof. Thechamber has an opening at one side, through which the arm 51 projects, and which is large enough to permit the arm limited pivotalmovement. The sides of this aperture form stops against which the sides of the finger 51 engage to limit its movement. It is normally held in the full-line position of Figure 4: by spring means, such as the spring 57 coiled about the pin 52, one end engaging the finger 51 and the other the arm 5. I Should the bearing members, either the finger 51 or the chains, 6 supported thereby, encounter an object, such as a large boulder, indicated at B in Figure 4, which might tend to impede the rotation of the stirring devices or to break them, the fingers 51 yield, if they are directly engaged, or if the chain 6 or 60 which they support is engaged, the chain and the arms supporting it all yield, as indicated in Figure 4 by dotted lines, to permit the stirring devices to pass the boulder and to continue the stirring action without damage.

The stirring device may be driven in any manner which is found suitable. To avoid complications of driving'from the motor of the truck, since the body must be hoisted for dumping, I prefer that the entire stirring device be driven from an electric motor 1?, which may be mounted upon the forward end of the dump body or upon an extension 14 thereof. This motor, which may be supplied with power from the trucks battery or from a special battery provided for the purpose, drives through any suitable reduction gearing, as indicated at 42, 43, 4 1 and 16 in turn (see Figure 3), the last of which is a gear attached to the forward end of the shaft 4.

The gate 3 is preferably hinged at its upper end, so that the concrete may slide out along the bottom, and since the load will ordinarily extend above the level of the hinge, it becomes necessary to provide some means to protect the hinge against cement, sand, dirt Y and the like. To this end, I form the fixed plate 13 with a slightly inwardly bent apron 15 (see Figure 6) and the hinge pin 31 is mounted outside of and above this level-for instance, upon brackets 32 supported from an angle bar 16, secured on the outer side of the fixed plate 13while the hinge member 33 is secured to a similar angle bar 34, secured to the upper edge of the gate 3. The upper edge of the gate extends just outside the apron l5 and above the lower edge of the apron, and substantially in line with the lower edge of the angle 16. Supported from this angle 16, or from a smaller angle 17 is a fairly thick strip of rubber, indicated at 18. When the gate 3 swings to closed position and is drawn shut by the lever 32 acting upon the catch 30, the upper edge of the gate presses into the rubber strip 18 and presses it against the edge of the angle 16. This forms a tight joint, and because it is located in a small pocket, indicated at P, air is trapped in this pocket and the concrete is thereby prevented from access to the rubber at 18, so that the later is never ncrusted with cement. Furthermore, when the gate opens, the rush of concrete down the base of the plate 13 and over the apron 15 efl'ects a suction which draws out of the pocket P any liquid material which may be there and effectively cleans this pocket by suction.

Such trucks as these are designed to be driven beneath concrete hoppers or mixers, where they receive their load, and suchinstallations must be kept as close to the ground as possible, hence it is not desirable that the stirring device extend above the other portions of the truck. It is for this reason that I have shown three such spider arms to a set, for with three arms, they can be so disposed, as is indicated in Figure 1, that none of them sticks above the edge of the body 1 to any considerable extent, and in no case do they project higher than the level of the cab when in this position.

Bearings, such as those at 4:0 and 4:1, and the knuckle joints, may be suitably packed to exclude foreign matter. Various means to this end, as is common practice, may be employed. The packing means have not been illustrated, since it is recognized that the same would be provided as a matter of course.

What I claim as my invention is:

1. In combination with. a part-cylindrical hopper truck body, longitudinaly extending flexible members disposed about the axis of the hopper at substantially the distance of its radius, and rigid members for supporting and rotating said flexible members to scrape the hopper bottom, said supporting members including a portion directly supporting the flexible members and yieldable inwardly upon encountering abnormal resistance. 1

2. In combination with a part-cylindrical hopper truck body, an axially extending shaft, spider arms disposed along said shaft, fingers yieldingly mounted upon theends of said arms, and flexible members extending longitudinally between the ends of the fingers, to contact the hopper bottom. I

- 8. In combination with a part-cylindrical hopper truck body, supports rotatable about the axis of said hopper, fingers projecting therefrom substantially to the hopper bottom, and flexible in the direction of rotation, and chains stretched from each finger to adjacent fingers along elements of the cylinder,

to scrape the bottom.

4. In combination with a bullet-nosed hopper truck body, supports rotatable about the axis or" the hopper through paths close to the bullet nose wall, and a flexible member stretched between said supports, said flexible memberbeing of increasing breadth from each point of support to a mid-point, whereby to scrape the inside of the bullet nose.

5. In combination with a bullet-nosed hopper truck body, supports rotatable about the axis oi. the hopper, through paths lying close to the bullet nose wall, and chains stretched between said supports, the links of said chains being of successively larger size from each support outward to a central link, whereby the chains scrape the inside wall of the bullet nose.

6. Incombination with a part-cylindrical hopper truck body, an axially extending shaftrotatable therein,'groups of three spider arms aligned and secured on said shaft at intervals therealong, a. finger pivotally mounted for limited movement in the plane of rotation at the outer end of each arm, stops .to limit movement of the fingers in one direction to a position where their path lies close to the inner wall of the hopper, a spring urging the finger and holding it against the stop, and a flexible member extending longitudinally from the fingers of one group of spiders to the corresponding finger of an adjacent group, whereby to scrape the inner wall of the hopper.

7. In a device of the character described, in combination, a rotatable spider arm having at its outer end a transverse end-opening cylindrical chamber, a cover enclosing said chamber, said chamber having a peripheral slot giving access to its interior, a finger pivotally mounted within the chamber and projecting through said slot, a part-cylindrical apron associated with said finger and closing the slot in all positions of the finger, and a coil spring within the chamber engageable with the arm and with the finger to hold the latter normally at one limit of its movement.

8. In a device of the character described,

in combination, a rotatable spider arm, a finger pivotally mounted upon the end of said arm, a spring acting upon said finger from the arm, stop means t0-ho1d the finger in a normal position, in opposition to the spring, and a flexible member supported upon the outer end of said finger, and extending parallel t0 the axis of rotation to like fingers, and a part-cylindrical hopper truck body, the spiders being rotatable therein to-scrape its bottom with said flexible members.

Signed at Seattle, Washington, this 1st day of May, 1931.

CLYDE B. MORROW. 

